The transportation of products for long distances frequently requires packing systems which are resistant and suitable to each type of material transported. Thus, for example, we have the transportation of automotive vehicle parts from the manufacturing plant to the assembling plant. The parts for assembling automotive vehicles are generally are made of metal with precision and uniformity and must get to the assembling line without any type of physical damage in their structure, mainly damages that can affect the use thereof or make them unusable, for they shall be processed in high-precision equipment in the vehicle assembling plant. Therefore, such damages as deformation of the structure, surface corrosion, scratches in parts made of plates and provided with surface treatment, and the like, are undesirable.
In view of such automotive industry demand, boxes have been developed, generally made of wood, for this is the most suitable material for that type of transportation, for satisfying all transportation needs such as safety, resistance, water-tightness, as well as ability to be piled up, deformed and disassembled. However, despite those industry demands, traditional boxes that cannot be disassembled are still in use, and for such reason have a short half-life and are not cost-effective, besides being clumsy and heavy to be handled, thus making it difficult to carry same.
There are at least two types of boxes in the market which can be fully disassembled and restored to their original shape that are frequently used in the automotive industry.
The first one, developed and patented in the name of the Applicant under number BR 6200841 and marketed under trade name Vicaixa.RTM., is provided with a base structure made of plywood and comprised of a bottom, four sides and cover which are fastened together by means of metallic angle bars having locking latches. Said angle bars are provided with teeth which are attached to the plywood surface by means of compression. The closing of the box is carried through by the locking of a latch provided in one of the sides of the pair of angle bars in a groove provided in the part in the opposing side of said pair of angle bars. A variant of that design, which can be partially disassembled, provides the joining of the sides together by means of a metallic ribbon which is also provided with teeth for attachment to the plywood surface, longitudinally positioned between each pair of sides. Said metallic ribbons make it possible to fold one side over the other.
Despite the fact that the above mentioned Vicaixa.RTM. satisfactorily fulfills the automotive industry requirements, it presents some problems connected with the maintenance and conservation thereof, since metallic parts, angle bars and ribbons are exposed over the box structure. This brings about the direct contact of metal/metal and/or metal/wood, thus damaging both the metallic parts and the wood structure of the box. However, this contact is not desirable while such boxes are transported and stored, for it causes the disruption of connecting portions of the box walls and consequently damage the product stored therein. In addition, after it is first disassembled, a traverse crease is created on the angle bar locking latch, what makes it difficult to be assembled a second time. Still, in view of the fact that the parts are made of metal, said box can only be made of 4 to 12 mm thick plywood.
The second design mentioned above, as well as improvements thereto and applications therefor, was developed by Clip-Lok International Limited, known by the trademark Clip-Lok.RTM., is described in published patent applications PCT WO 95/13969, WO 94/25355 and WO 93/17930, in Brazilian patent application BR 9305437-8 and in GB patent GB 2 257 453. Like the above mentioned Vicaixa.RTM., Clip-Lok.RTM. is also provided with a base structure made of plywood and comprised of in compensated bottom plates, four sides and cover fastened together by means of metallic staples or clips which can be placed under pressure into recesses provided in the surfaces of said plywood plates, thus keeping them locked to one another. After being attached, said metallic staples are removed when disassembling the box by the use of a special tool.
Said Clip-Lok.RTM. system, however, in spite of also satisfying the automotive industry needs, has its intrinsic difficulties and disadvantages. When the box is assembled, if said clips have not been suitably attached, they can slacken under pressure while being transported. An assembled box lacking a clip is a box without the required safety for transportation and storage, for it can collapse due to the inner and/or outer pressure thereon caused by the oscillation while it is transported. The clip is attached to and removed from the box under pressure and therefore such a submission makes it a short half-life part. Furthermore, said Clip-Lok.RTM. is also a box having exposed parts on its surface, what can, as already stated, cause the direct contact of metal/metal and/or metal/wood, thus damaging both the metallic parts and the wood structure of said box.
Still, a common fact with the above mentioned boxes is the lack of a suitable isolation therein of the product against external agents, such as water and/or sea water when transported by ship, which agents permeate into the box interior through its cover.